As far as gun safety advocates are concerned, Maryland has some of the best laws in the country. In addition to the prohibition on leaving guns where minors might have access to them, gun dealers are required to sell only weapons with a "integrated mechanical safety device" that is "designed to prevent the handgun from being discharged unless the device has been deactivated." Older guns that lack such safety features must be sold with an external safety lock that achieves the same purpose. The state maintains a roster of handguns eligible for sale in the state, evaluated for, among other things, "reliability as to safety." And Maryland is one of only three states with laws related to so-called "smart gun" technology. The Handgun Roster Board is required to report annually on the status of guns with integrated technology that prevents them from being fired by anyone other than an authorized user. Such guns either use biometric identification, such as fingerprints, or for the user to be carrying some kind of token, like a watch or key fob, that communicates with the gun. Finally, the Gun Safety Act of 2013 requires a gun safety course for those who apply for handgun purchase licenses, and that training includes safe storage techniques for guns in the home.